Index Locomotives - books DIESEL LOCOMOTIVE OPERATING NO. 2315 for MODELS F9, FP9, FL9 - manual 1997 year
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ELECTRICAL
F9-5-657
508
ER Relay
The ER relay controls the current supply to the
A, B, and C governor control solenoids. The ER relay has no control of
the D governor control solenoid, which is used to shut the engine down.
The D solenoid is energized in throttle positions STOP, Run 5 and Run
6. De-energizing the ER relay with the throttle in Run 5 or 6, will cause
the engine to shut down. De-energizing the ER relay in any other throt-
tle position will automatically reduce the speed of the engine to IDLE.
To control the engine speed in any unit, the ER relay in that unit
must be energized. The ER relay has three normally open interlocks
which will close, when the relay is energized, to connect the control
circuits to the A, B, and C governor control solenoids, Fig. 5-9.
The ER relay in each unit is energized by current received from
the FP wire that runs throughout the
locomotive. For current to flow through
the FP wire to the ER relay; the main
battery and control knife switches must
be closed, the "Engine Run" switch at
the engineman's control panel must be
ON, the ground relay must be set, the
PC switch must be closed (PC light out),
the isolation switch must be in RUN and
the NVR relay must be energized
(engine must be running).
509
Battery Field Contactor And
Fuse
When the throttle is moved to Run
1 this contactor, Fig. 5-10, closes and
connects low voltage excitation to the
main generator battery field. The battery
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field (BF) contactor remains closed as long as power is being applied,
but will open during transition 2 to 3 and 3 to 2 and wheel slip action to
reduce main generator output.A rectifier and discharge resistor are used
to dissipate the high voltage induced in the battery field when the BF
contactor is opened.
An 80 ampere battery field fuse, located in the low voltage
panel protects the battery field circuit. If the fuse is blown, the unit will
not develop normal power.
510
Wheel Slip Control
The wheel slip control system goes into
operation the moment that the slipping of a pair of wheels is detected
while under power. Four wheel slip control relays, WS13, WS24, WSS,
and WCR, located in the electrical cabinet, are of the through able type,
Fig. 5-11.
The WS13-24 relays are operated
by two sources: (1) by a flow of current
through the relay coil with the traction
motors connected in series-parallel or
series-parallel shunt. Current will flow
through the relay coil, when an unbalance
in the bridge circuit between two 2000
ohm resistors and two traction motors,
which the relay coil bridges, occurs as a
result of a "slipping" motor. (2) By a
current differential between the cables that
pass through the relay frame with the
traction motors connected in parallel or
parallel shunt. These cables are so ar-
ranged that the normal current flow
through them is of equal magnitude and in
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opposite directions. Thus, the magnetic field established by the current
flow in one cable is nullified by the magnetic field established by the
current flow in the second cable. When an unbalance in the current
flows occurs as a result of a "slipping" motor, the resultant magnetic
field established actuates the WS relay.
The WCR (wheel creep relay) and WSS (wheel slip series) are
operated only by a current differential between the cables that pass
through the relay frame, with the traction motors connected in series -
parallel or series-parallel-shunt.
Automatic sanding in power occurs through the action of the
WCR relay. The WCR is used to detect very slow creeping type slips.
The function of the WCR, having a slightly lower pickup value than the
WSS and WSR, is to apply sand automatically to the rails which tends
to prevent a wheel slippage necessitating the reduction of generator
field excitation.
When WCR picks up, it energizes the time delay sanding relay
(TDS). "Picking up" of the TDS automatically actuates the forward
sanding valve, applying sand to the rail.
At very slow speeds, if the wheel slip cannot be corrected
through the action of the WCR applying sand to the rails, the WSS
picks up to reduce main generator excitation. When the WSS picks up,
the wheel slip light will flash ON and the battery field contactor (BF)
will open. Opening the battery field contactor, "cuts out" the main gen-
erator battery field excitation and causes the overriding solenoid (ORS)
to move the load regulator toward the minimum field position. This ac-
tion will generally correct the wheel slip, and it should not be necessary
for the enginemen to reduce the throttle. The function of the WSS relay
is to recognize slow speed wheel slips and effect a slip correction with
a minimum loss of tractive effort.
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ELECTRICAL
If further reduction of main generator excitation is necessary to
correct the wheel slip, the WS relay, actuated by a current flow through
the relay coil, picks up and opens both the battery and shunt field con-
tactors, reducing the excitation of the main generator to a point where
slipping stops. The time delay sanding valve (TDS) is energized, auto-
matically applying sand to the rails. When the shunt field contactor
opens, an additional resistance is added into the shunt field circuit re-
sulting in a further but controlled unloading of the main generator.
Opening the battery field contactor energizes the ORS, and the load
regulator moves toward the minimum field position. Thus, as soon a s
the slipping stops, the WS relay will drop out, and power will auto-
matically be reapplied at a lower level than that at which the slipping
was initiated. The application of power will then gradually return to
that designated by the position of the throttle.
To correct high speed wheel slips with the traction motors con-
nected in parallel or parallel-shunt, either of the WS relays actuated by
a current differential between traction motors 1 and 3 (WS13) or 2 and
4 (WS24) will pick up to reduce main generator excitation to a point
where slipping stops.
Since sand is automatically applied to the rails during a wheel
slip detection, it should be unnecessary for the enginemen to operate
the manual sanders. If continuous wheel slipping on sand occurs, the
throttle should be reduced.
511 Main Battery Switch
This switch is located on the distribution
panel and connects the 32 cell, 64 volt, 426 ampere-hour capacity (8
hour rating) battery to the low voltage circuits. An external charging re-
ceptacle is located on the left side of the locomotive. To start the Diesel
engine and during normal locomotive operation, the main battery
switch should be closed.
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F9-5-657
512
Battery Ammeter
The battery
ammeter is visible through an opening
on the front side of the electrical
cabinet. This ammeter, Fig. 5-12, only
shows whether the battery is charging or
discharging. Normally the meter will
indicate zero or a slight charge. If a
continual discharge is shown, the aux-
iliary
generator
output
should
be
checked, or the battery may run down.
513
Reverse Current Relay
This relay,
Fig. 5-13, located on the low voltage
panel, controls the opening and closing
of the battery charging contactor (BC). The RCR causes the BC contac-
tor to open w h e n the
auxiliary
generator
voltage
drops
below
the
battery
voltage.
This
prevents
a
reverse flow of current from
the battery attempting to "mo-
tor" auxiliary generator.
514
Battery
Charging
Contactor
This
contactor
is
an
electrically
operated
switch
connecting
the
auxiliary generator output to
the low voltage system. The
reverse current relay controls
the operation of the battery
charging contactor.
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515
Ground Relay
The ground relay, Fig. 5-14, located in the elec-
trical cabinet, is an electrical protective device connected to the high
voltage system. The function of this relay is to unload the main genera-
tor automatically in case of a ground in the high voltage system (a
ground can be defined as a current passing through the frame, or car-
body, of the locomotive).
If a ground in the high voltage
system should occur, the ground relay
will trip. When tripped, the ground r e
l a y opens the shunt and battery field
contactors,
unloading
the
main
generator. The ground relay must be
reset before the unit can again deliver
power. The relay is reset by pressing
in an the remote reset button. If the
relay repeatedly trips when power is
applied, the power plant MUST be
isolated.
CAUTION:
Isolate
unit
before
resetting the ground relay.
With ground relay tripped, the speed
of the engine will be automatically
reduced to Idle. If the ground relay
tripped while the throttle was in the
5th or 6th notch, the engine would stop.
Although a high voltage ground will normally be the only rea-
son for the ground relay tripping, a low voltage ground can trip the re-
lay when the engine is started; since at that time the high and low volt-
age systems are temporarily connected. Ground relay action is not
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necessarily an indication of serious trouble but should be reported to
the maintenance authorities.
The ground relay knife switch, when open, eliminates the pro-
tection of the ground relay. This switch MUST NOT BE OPENED in
normal operation unless definite instructions are issued by an official of
the railroad.
516
Voltage
Regulator
The voltage regulator,
Fig. 5-15, is located in the
electrical cabinet. The voltage
regulator performs the function
of seeing that the output voltage
of the auxiliary generator re-
mains at approximately 74 volts
whenever engine is running.
517
Auxiliary
Generator
Fuse
(Battery
Charging)
This 150
ampere fuse, Fig. 5-16, located
on
the
low
voltage
panel,
protects the auxiliary generator against any possible overload. A blown
auxiliary generator output fuse will cut off the auxiliary generator from
the low voltage system and the alternating current system. The battery
ammeter will indicate a discharge when this fuse is blown, the alarm
bell will ring, and the "Alternator Failure" light (blue) will flash on in
the unit affected.
518
Auxiliary Generator Field Fuse
This 30ampere fuse protects the
auxiliary generator field windings against excessive current, Fig. 5-16.
Blowing of this fuse will prevent the auxiliary generator from
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supplying current to the low voltage system and alternating current sys-
tem. With this fuse blown, the battery ammeter will indicate a dis-
charge, the alarm bell will ring, and the "Alternator Failure" light (blue)
will flash on in the unit affected.
519
Alternator Field Fuse
This 35-ampere fuse, located on the low
voltage panel, protects the alternator field, Fig. 5-16. If blown, the
alarm bell will ring and the "Alternator Failure" light (blue) will flash
on in the unit affected.
1. Auxiliary Generator Switch
4. 80A Battery Field Fuse
2. RCR – Micropositioner
5. 35A Alternator Field Fuse
3. 150A Auxiliary Generator
6. 30A Auxiliary Generator
Fuse
Field Fuse
Low Voltage Panel
Fig. 5-16
520
No AC Voltage Relay (NVR)
As the traction motors are
cooled by AC driven blowers, failure of the alternator could result in
damage to the traction motors unless the application of power was
stopped. Thus, in case of an alternator failure, the NVR, Fig. 5-17, lo-
cated on the low voltage panel, drops out and causes the alarm bell to
ring in all units. The "Alternator Failure" light (blue) will flash on, and
the engine speed will be reduced to idle in the unit affected (if the throt-
tle was in the 5
th
or 6
th
notch the engine would stop).
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